In processing for silver halide color photographic materials, after image-exposure, the color photographic materials are usually developed by a color developer containing an aromatic primary amine color developing agent. During this processing the silver halide is reduced to form developed silver and at the same time the color developing agent itself is oxidized, which then reacts with a coupler to form an intermediate (leuco compound) of the colored dye. Thereafter, developed silver is rehalogenized by a bleach solution and removed by a fix solution or is oxidized and removed by a blix solution. Also, the colorless leuco compound is oxidized by a bleaching agent in the bleach solution or the blix solution to form a colored dye.
Recently, speed up of processing is required to improve the producibility and reduce the processing cost and, thus, a color development is performed without employing a stop bath between a color development bath and a bleach bath or a blix bath and further, as the case may be, a wash bath is also omitted. Hence the light-sensitive materials are frequently processed in a bleach solution or a blix solution in the state of insufficient washing out of the color developing agent from the light-insensitive materials.
Furthemore, recently, reduction of the using amount of a bleach solution or a blix solution as well as reduction of the discharging amount thereof are required from the viewpoints of the reduction in cost and the regulation of pollution. Hence, a method is proposed wherein the amount of a supplementing solution is reduced or the overflowed solution is recovered and reused (Japanese Patent Publication No. 33697/81 (corresponding to U.S. Pat. No. 3,707,568)). In such a case, the components of the color developer carried in a bleach solution or a blix solution are accumulated therein, and a color developing agent of the accumulated color developer is liable to be oxidized by a bleaching agent and react with a remaining coupler to cause color fog. Also, when a bleaching agent does not show a sufficient oxidizing power due to the occurrence of fatigue, etc., a part of the leuco compound is not converted into a colored dye but remains as the leuco compound, thereby a sufficient color density cannot be obtained.
In particular, when performing blix processing, since the oxidizing power of a bleaching agent is relatively weak, the leuco compound is reluctant to become a colored dye or a colored dye is reduced to form a leuco compound by the reducing agent carried in the blix solution from a color developer or by the reducing agent in the blix solution to reduce the color density. Accordingly, sufficient color reproduction cannot be obtained. Such a phenomenon is particularly remarkable in the case of a cyan dye. That is, a cyan dye is liable to become a leuco compound which results in great reduction of color density.
The present inventors have carried out investigations and confirmed that when benzyl alcohol contained in a color developer is largely accumulated in a bleach solution or blix solution as the results of reducing the supplementing amount of a bleach solution or blix solution or reutilizing an overflowed solution, washing out of color development components from color photographic materials is delayed. This causes substantial formations of color stains and leuco compounds. Thus, it becomes necessary to investigate a method of preventing the formation of leuco compounds and color stains from a viewpoint different from conventional methods.
A known method for preventing the formation of color stains involves adding a p-aminophenol to a bleach solution or a blix solution as described in British Pat. No. 1,133,500. Another known method involves adding an amine to a bleach solution containing persulfuric acid as described in U.S. Pat. No. 3,707,347. However, when these methods are used, color turbidity occurs or the effect of preventing the formation of color stain is insufficient.
British Pat. No. 1,132,339 describes a method of adding a 3-pyrazolidone to a bleach solution or a blix solution. However, the method does not take into consideration the fact that the bleach solution or blix solution forms a substantial amount of leuco compounds with benzyl alcohol contained therein at a high concentration.
Various methods for preventing the formation of leuco compounds have been investigated. For example, as an improvement for processing solution, there is provided a processing method of separately forming an oxidizing bath containing a material having a strong bleaching power, such as a ferricyanide, a dichromate or a ferric salt. However, the use of such a compound is undesirable with respect to both obstructing the speed up of processing and environmental contamination. Another method provides for increasing the concentration of an aminopolycarboxylic acid iron salt as a bleaching agent as described in Japanese Patent Application (OPI) Nos. 3340/71 (corresponding to U.S. Pat. No. 3,706,561) and 5630/74 (corresponding to British Pat. No. 1,393,335) (the term "OPI" as used herein refers to a "published unexamined Japanese patent application). However, such a method is not always preferred since the cost for processing becomes high and further the stability of the processing solution is reduced.
Another known method involves adding a compound such as ethylene oxide, a mercapto compound, a p-aminophenolic compound, and amine series compound, etc., to a bleach solution or a blix solution. However, this method is still unsatisfactory since color turbidity occurs and the effect of preventing the forming of leuco compounds is less.
Other known methods of improving color photographic materials include a method of using fluorine series cyan couplers as described in Japanese Patent Application (OPI) Nos. 137137/75 and 65953/80, a method of using an organic acid ester as an oil for emulsification as described in Japanese Patent Application (OPI) No. 52533/79 and Japanese Patent Publication No. 2335/81, and a method of incorporating paraffin in a red-sensitive silver halide emulsion layer and/or a layer adjacent to the emulsion layer as described in Japanese Patent Application (OPI) No. 99432/79. However, these methods are unsatisfactory because development is delayed and the effect of preventing the formation of leuco compounds is less.